Investigators are still searching for a motive for the mass shooting in Washington D.C.'s Navy Yard, as the facility reopened for business Thursday morning.

All buildings were reopened at the Navy Yard except building 197 (where the shootings occurred) and the base gym, which is being used by investigators.

Recent revelations suggest that budget cuts prevented security forces at the base from being able to properly defend against the attack. Additional information revealed that Alexis was granted access to the base as a contractor based on a five-year-old background investigation, which took place before his run-ins with police and reported mental issues.

Based on a report by the Los Angeles Times, the government largely relies on the honor system for the 4.9 million people who hold security clearances. An employer is expected to report any brushes with police or signs of mental illness that occur with one of their employees. Aside from checks to ensure that companies are in compliance, the government faces an uphill battle when it comes to being up-to-date on the status of all those with security clearances.

There also appears to be a breakdown of communication between bases. According to USA Today, a Navy base in Newport, R.I. failed to pass along information that included an incidence of Alexis hearing voices. According to Newport police, Alexis said that an unknown people were preventing him from sleeping and sending "vibrations" through his body.

According to a source, information about Alexis was not passed on the the D.C. base or his employer because they "did not deem Alexis to pose a threat to himself or others." The shooter had reached out for help with insomnia twice over the past month, heading to two emergency rooms where he was prescribed Trazodone. During a visit he was asked about having feelings of depression or anxiety, or thoughts of harming himself or others, all of which he denied.

On Wednesday, Alexis' mother made her first statement since the shooting from her home in Brooklyn. In a taped recording she said, “I don’t know why he did what he did, and I’ll never be able to ask him why. Aaron is in a place where he can no longer do harm to anyone. For that I am glad.”

The massacre brings the question of gun control back to the forefront of the political arena. Alexis legally purchased the shotgun used during the shootings — after passing a background check — but was prevented from purchasing a more high-powered assault rifle thanks to a law that prohibits the sale of the weapons to out-of-town buyers. The shooting, practically next-door to the halls of Congress where beefed-up gun control laws were struck down earlier this year, will certainly renew the debate on the need for stricter background checks and more closely monitored weapons sales in the coming months.